Portable exercise machine



FIG. 1 is a front and upper left perspective view of the portable exercise device showing my new design;

FIG. 2 is a bottom and lower left perspective view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a right side elevational view thereof;

FIG. 7 is a front end elevational view thereof; and,

FIG. 8 is a rear end elevational view thereof. 

CLAIM The ornamental design for a portable exercise machine, as shown and described. 